I have "samll" proble. I just bought a Wacom 9x12 and was satisfied with it first day. but after that pressure sensivity sometimes desappear when I use Photoshop. Like if i make one stroke and opacity for example was made by pressure, but next stroke is 100% opace. Its totaly brake my will to draw. I even thing to switch to Painter if I won't find why this happens. Any ideas?

What computer are you using? PC or mac?
serial port or usb?
make sure you have the latest drivers for you tablet, visit www.wacom.com and download the drivers for your tablet.
If anything like what your mentioning happens, it's usually the driver for the tablet.
Make sure you read the instructions before you install the new driver. you usually have to un-install the old driver before you attempt to install the new one. If you don't, things will not work correctly, or the drivers will fail to install.
Hope this helps.

I have 1ghz Athlon 512Ram etc.
Tablet is 9x12wacom
The thing is that it works in other apps.
And I guess I have the latest driver. At least I just bought a tablet, not a year ago And the driver number happen to be the same as the latest on wacom.com. but I must check on that. BTW. why don't they make their site wa.com ))
another Q: What the difference between Painter Classic and Painter 6.x ? I got Classic for "free" with my tablet

TheNexx thanx for the info I have the same problem and I used Painter Classic as a result of it. The pressure sensitivity seemed to work better Painter 6 is cool also it has alot more textures and brushes and what not and most importantly it supports layers. It's actually the Photoshop for sketching. Let me know if the latest driver improves your experience.

Im using win2k, and I do not have these problems. Your best bet is to call wacom and ask them. They are very helpful and nice people. And you'll learn the ever burning question "how do you pronounce WACOM" That's how I learned the correct way of pronouncing it...anyway...
They can probably help you out, it could be a faulty tablet also, make sure you have the latest service pack for win2k and critical updates as well.
Some things to try...

un-install your driver, unplug your tablet. Shut down your computer.

attach your tablet, power up your computer, re-install the drivers. test to see if the pressure sensitivity is working by opening the wacom control panel and testing it in the small drawing area.